black fly

	1.	(Zool.) In the United States, a small, venomous, two-winged fly of the genus Simulium of several species, exceedingly abundant and troublesome in the northern forests; - called also buffalo gnat. The larvæ are aquatic. It sucks the blood of birds as well as humans and other mammals.
	2.	A black plant louse, as the bean aphis (Aphis fabæ), which infests e. g. beans and sugar beets; - called also bean aphid.

Noun

1.

black fly - small blackish stout-bodied biting fly having aquatic larvae; sucks the blood of birds as well as humans and other mammals Synonyms: buffalo gnat, blackfly

blackfly, buffalo gnat, genus Simulium, gnat, Simulium